Galactose-α-1,3-Galactose–Specific IgE Is Associated with Anaphylaxis but Not Asthma

Rationale: IgE antibodies to the mammalian oligosaccharide galactose-α-1,3-galactose (α-gal) are common in the southeastern United States. These antibodies, which are induced by ectoparasitic ticks, can give rise to positive skin tests or serum assays with cat extract

The Glycosylation Pattern of Common Allergens: The Recognition and Uptake of Der p 1 by Epithelial and Dendritic Cells Is Carbohydrate Dependent

Allergens are initiators of both innate and adaptive immune responses. They are recognised at the site of entry by epithelial and dendritic cells (DCs), both of which activate innate inflammatory circuits that can collectively induce Th2 immune responses. In an attempt to have a better understanding of the role of carbohydrates in the recognition and uptake of allergens by the innate immune system, we defined common glycosylation patterns in major allergens. This was done using labelled lectins and showed that allergens like Der p 1 (Dermatophagoides pteronyssinus group 1), Fel d 1 (Felis domisticus), Ara h 1 (Arachis hypogaea), Der p 2 (Dermatophagoides pteronyssinus group 2), Bla g 2 (Blattella germanica) and Can f 1 (Canis familiaris) are glycosylated and that the main dominant sugars on these allergens are 1–2, 1–3 and 1–6 mannose. These observations are in line with recent reports implicating the mannose receptor (MR) in allergen recognition and uptake by DCs and suggesting a major link between glycosylation and allergen recognition. We then looked at TSLP (Thymic Stromal Lymphopoietin) cytokine secretion by lung epithelia upon encountering natural Der p 1 allergen. TSLP is suggested to drive DC maturation in support of allergic hypersensitivity reactions. Our data showed an increase in TSLP secretion by lung epithelia upon stimulation with natural Der p 1 which was carbohydrate dependent. The deglycosylated preparation of Der p 1 exhibited minimal uptake by DCs compared to the natural and hyperglycosylated recombinant counterparts, with the latter being taken up more readily than the other preparations. Collectively, our data indicate that carbohydrate moieties on allergens play a vital role in their recognition by innate immune cells, implicating them in downstream deleterious Th2 cell activation and IgE production

Analytical nonlinear reluctance model of a single-phase saturated core fault current limiter

A saturated core fault current limiter (FCL) is a device that is designed to limit the fault currents in electrical energy networks and consequently, protect existing network equipment from damage. Due to complex nonlinear magnetic properties, the performance of saturated core FCLs has largely been characterized through experimentation and finite-element analysis simulations. Although both of these techniques are quite accurate, they are time consuming and do not describe the behavior of FCLs in actual electrical networks. This has led to an increasing demand for an accurate analytical model that is suitable for transient network analyses. This paper presents the development of an analytical model of a single-phase open-core FCL, which accurately describes the nonlinear magnetic properties of the FCL through a reduced reluctance approach. The extension of this model to other saturated core FCL arrangements (such as closed core) is also discussed. © 1986-2012 IEEE

Development and analysis of two alternative tubular linear motors for use in machine tools

The manufacturing industry is relying on faster and more accurate positioning systems in machine tools to meet the increasing demand of higher machining tolerances. Improvements in positional accuracy, smoother velocity control at low speeds and higher bandwidth in speed and acceleration have been the focus of many researchers over recent years. This thesis is concerned with the modelling and development of two different high precision tubular linear synchronous motors which are potential alternative direct drive actuators in present day machine tools. The investigations include the analysis, design, manufacturability and control of a slotless Permanent Magnet Tubular Linear Motor (PMTLM) and a Synchronous Reluctance Tubular Linear Motor (SyncRTLM) through appropriate modelling, construction and experimental validation. The most significant contributions of this thesis are: • The analysis of the cogging force in the PMTLM taking into account the finite length of the stator. An appropriate model is developed using Finite Element Analysis (FEA) tools and experimentally verified. • The SyncRTLM with a laminated stator is modelled and experimentally verified for the first time. The tubular topology gives rise to a number of unique and novel optimisations which are presented in this thesis. • A novel commutation technique for the SyncRTLM is developed and customised code is developed in an industrial controller to achieve accurate servo control. • Two innovative manufacturing techniques were developed, one to facilitate the manufacture of the magnet structure for the PMTLM, and one which enables practical production of the SyncRTLM anisotropic stator. FEA models of the two motors including simulations of the force characteristics are presented. Experimental validations of the FEA analyses are carried out. Proposals for construction and manufacturing techniques for the motor production are also given

Cogging force analysis of a slotless tubular linear motor with finite stator

Permanent magnet tubular linear motors have shown potential for use as direct drives in high precision applications such as machine tools. These devices have the ability to overcome or reduce many of the fundamental mechanical properties that limit the precision performance of traditional rotary to linear translation mechanisms, such as the ball screw. However, the cogging of the motor must be minimised for high precision applications. Previous work has assumed an infinite stator length, but this approach has limitations. This paper investigates the cogging force of a slotless tubular motor with a stator of finite length using finite element analysis. To assist with optimal design, the influence of different stator lengths and end effects is presented. Experimental data is given for validation

Design considerations in MgB2-based superconducting coils for use in saturated-core fault current limiters

Saturated-core fault current limiters (FCLs) are devices that have many applications and potential for use within power networks. At a commercial scale, these devices require high H-field magnets to saturate the steel core, which can typically only be achieved through the use of superconducting coils. Here, we present several challenges that arise in the application of superconducting coils in FCLs and discuss how to address these issues through a case study MgB2-based coil. It is found that significant ac magnetic fields, Lorentz forces, and Joule heating in components occur during normal and fault operations; however, these issues can be mitigated when properly addressed

Three phase saturated core fault current limiter performance with a floating neutral

High power demands in electricity grids are continually increasing. This increasing trend coupled with the introduction of renewable energy sources, which require energy storage devices, poses significant problems to fault current levels. To improve network availability and grid resilience, superconducting saturated core Fault Current Limiters (FCL) are a suitable solution to reduce high fault currents in distribution level electricity grids. These devices have the characteristic of low impedance to the network during normal operation and high impedance during a fault event. However, this change in impedance is nonlinear and can lead to an imbalance in a three phase saturated core FCL. In this paper, the effects on fault current limiting performance due to the unbalanced instantaneous impedance between the 3 phases are investigated. The FCL fault transients of a grounded fault and a floating fault are simulated and compared using Finite Element Analysis (FEA) techniques. The presented results are also validated against a real world distribution level saturated core FCL under high power testing. © 2012 IEEE